Fluid handling and distributing system

ABSTRACT

A system for handling and distributing fluid is disclosed, which system is particularly useful for handling and distributing coating materials utilized in applying a thin metallic oxide coating to the outer surface of glass containers. The system includes readily accessible and replaceable bulk storage, preferably including a plurality of receptacles such as storage barrels, which receptacles are caused to selectively and successively supply fluid (which fluid may be chemicals such as titanium tetrachloride, tetraisopropyl titanate, or tin tetrachloride, for example, where a metallic oxide coating is to be applied to a newly formed glass container) to a reservoir which in turn has the fluid pumped therefrom and supplied to a remotely located master tank. The master tank is connected to the reservoir in a manner to maintain a substantially constant fluid level therein, and level monitoring apparatus is provided in the master tank. One or more slave tanks are connected with the master tank and each is maintained at a predetermined fluid level with respect to the master tank. Each slave tank is preferably adjacent to and is connected with a utilization station, which station is an article coating station where newly formed glassware is to be coated with a thin metallic oxide coating. The system is automatic in normal operation and indications of deviations in fluid level of the master tank beyond both predetermined minimum and maximum levels are provided by the monitoring apparatus and normal operation is then terminated.

United States Patent T191 Bitner [111 3,805,821 [451 Apr. 23, 1974 154]FLUID HANDLING AND DISTRIBUTING SYSTEM [75] Inventor: Jay A. Bltner,Buffalo Grove, Ill.

[73] Assignee: Ball Corporation, Muncie, Ind.

[22] Filed: Nov. 30, 1972 [21] Appl. No.: 311,017

[52] U.S. Cl. 137/255, 137/263 [51] Int. Cl Gd 7/06, F16k 21/18, E03b1/00 [58] Field of Search 137/563, 565, 577, 571,l37/575;117/107,119;164/156,15 A, 155; 65/66, 181; 257/63; 118/7, 8,636, 49, 49.1; 184/616; 134/57 [56] References Cited UNITED STATESPATENTS 2,998,056 8/1961 Capehart 137/263 1,942,859 1/1934 Hickman137/263 X 2,457,903 l/l949 Kantor et a1. 137/263 X 1,329,997 2/1920 Page137/255 1,990,881 2/1935 Ruhlin 137/263 X 2,548,003 4/1951 Davidson137/266 X 3,312,189 4/1967 Mcvey 118/7 3,428,072 2/1969 Welch 137/263 X3,358,706 12/1967 Tischbein ..137/263 Primary Examiner-Henry T.Klinksiek Assistant Examiner-Robert J. Miller Attorney, Agent, orFirm-Gilbert E. Alberding [57] ABSTRACT A system for handling anddistributing fluid is disclosed, which system is particularly useful forhandling and distributing coating materials utilized in applying a thinmetallic oxide coating to the outer surface of glass containers. Thesystem includes readily accessible and replaceable bulk storage,preferably including a plurality of receptacles such as storage barrels,which receptacles are caused to selectively and sue, cessively supplyfluid (which fluid may be chemicals such as titanium tetrachloride,tetraisopropyl titanate, or tin tetrachloride, for example, where ametallic oxide coating is to be applied to a newly formed glasscontainer) to a reservoir which in turn has the fluid pumped therefromand supplied to a remotely located master tank. The master tank isconnected to the reservoir in a manner to maintain a substantiallyconstant fluid level therein, and level monitoring apparatus is providedin the master tank. One or more slave tanks are connected with themaster tank and each is maintained at a predetermined fluid level withrespect to the master tank. Each slave tank is preferably adjacent toand is connected with a utilization station, which station is an articlecoating station where newly formed glassware is to be coated with athinmetallic oxide coating. The system is automatic in normal operation andindications of deviations in fluid level of the master tank beyond bothpredetermined minimum and maximum levels are provided by the monitoringapparatus and normal operation is then terminated.

6 Claims, 6 Drawing Figures n |2'\ COATING COATING MATERIAL MATERIALSUPPLY SUPPLY ALARM ALARM RESERVOIR CIRCUITRY INDICATOR 42 43 l l; i 7 7ARTICtE ARTICLE ARTICLE ARTICLE COATING COATING PUMP COATING COATINGSTATION STATION STATION STATlON I l L 34 39 23 24 32 I37 3 38 7 l T I lT l l 7 T L SLAVE l SLAVE MASTER f LEVEL SLAVE SLAVE TANK TANK l TANKINDICATOR TANK TANK i ATENTEBAPRZBIHH v 3.805821 SHEET 2 [IF 4 IPATENTED 2 IHII I 3305821 SHEET U [1F 4 I no V C 60 CYCLE POWER A OFF 1ON FUSE L H4 I 3 Ill H8 I) POWER ON TEST I PUMP ON I I257 OFF .vC L I277msw I u I4I 3V4 H29 STOP I3 START 5 (FIELD) STOP 1 P MOTOR I43 A) OCONTROLLERm I32 8 Z MART v I42 IsI, PUMPON I38 I39 M 445 I46? PuMwToR llM L I48 lso kj |5l 521 5,53 I547 FLUID LELELALARM V I- V L456 I FLUIDLEvEL HIGH l5? I627 V XFN I64 465 I68 j FLUID LEVEL HIGH L 166M 5H5? Q QI59 o 1 I FLUID Ligalgmlfg l6l HGH Iss M 475 FILUID Z O G FLUID LEvELLOW L vEL S1 Q WSW ZI77 I69 wwo A |7| Low I Ivs mo FLUID LEVEL F 'g 6BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention relates generally to a fluid handling and distributing systemand more particularly to a system for handling and distributing coatingmaterials used in applying a thin metallic oxide coating to the outersurface of glass articles.

2. Description of the Prior Art It is oftentimes necessary, or at leastdesirable, to provide a tank or other receptacle for a particular fluidat a utilization station. Such a need can occur, for example, in theproduction of glass containers where a protective coating is commonlyapplied to the surface of a newly formed container while the containerstill retains sufficient heat from formation to cause a metallic oxidecoating to be formed on the surface of the container when the containeris exposed to fluid which includes a heat decomposable metalliccompound. Where such a metallic oxide coating is to be applied to aglasscontainer, such a fluid normally comprises a gas inert to the coatingmaterial, such as dry air, and a heat decomposable metallic compound,which may be formed by injecting dry air into the bottom portion of atank containing the coating material and allowing the air to passupwardly through the coating material. As a result, a vapor includingthe coating material is expelled from the tank under pressure andintroduced into the article coating station, commonly a hood or otherenclosure, and articles to be coated are then passed through the hood.Treatment of glass articles to coat the same by introducing a vapor intoa hood is shown, for example, in U. S. Pat. No. 3,615,327, while theformation of a vapor that includes a metallic coating compound ascoating material is shown, for example, in U. S. Pat. Nos. 3,561,940 and3,516,811.

In forming a vapor suitable for applying a thin metallic coating toglass articles as described hereinabove, it has been found to benecessary and/or at least desirable to provide a closed system tomaintain the level of coating material in the tank within certainpredetermined limits. A closed system is important since, as brought outin U. S. Pat. No. 3,615,327, at least some ofthe me tallic vaporsutilized (and hence presumably the coating materials) are stated to becorrosive in nature, and, moreover, each opening of the system (asnecessary for replenishing of coating material) can allow entrance ofunwanted moisture. Level maintenance of coating material in the tank isalso important since the level of coating material will, at least inpart, determine the amount of coating material included in the resultingvapor produced where such a vapor is produced by passing the inert gasupwardly through the liquid coating material.

I-Ieretofore, it has been a common practice to provide a separate unitfor supplying each articlecoating station and manually monitoring eachunit to determine when necessary to replace and/or refill the same. Inaddition, while reclaiming of treating material with subsequentreintroduction into a supply receptacle has heretofore been suggestedfor usage, vapors exhausted from article coating stations are often notso utilized, and automatic maintenance of the level of coating ortreating material has not been utilized in such known systems. Likewise,apparatus for monitoring the level of one or more tanks of coatingmaterial to 'guard against unwanted level deviations have not been foundin prior handling and distributing systems of this type.

SUMMARY OF THE INVENTION This invention provides a closed system forhandling and distributing fluids that is simple and inexpensive, yet isdependable, and provides both level maintenance and automatic fluidsupply, as well as automatic level monitoring.

It is therefore an object of this invention to provide a simple andinexpensive, yet dependable, system for handling of fluids.

Another object of this invention is to provide a system that is suitablefor automatically providing coating material in liquid form to one ormore article coating stations from a supply source that may be remotelysituated for convenience.

It is yet another object of this invention to provide a system forhandling and distributing fluids that automatically maintains a desiredlevel at one or more tanks each of whichis associated with a utilizationstation. 7

It is still another object of this invention to'provide a system forhandling and distributing coating material in liquid form that issuitable in providing a common reservoir of such coating material andsupplying the same to one or a plurality of coatingstations with theliquid level at each station being automatically maintained relativelyconstant.

It is still another object of this invention to provide a system forhandling and distributing coating material that includes as part of thesupply source, a plurality of storage receptacles that are automaticallyselectively connected with a reservoir supplying coating material to oneor more article coating stations.

It is still another object of this invention to provide a system forhandling and distributing fluids that includes automatic levelmonitoring.

With these and other objects in view which will become apparentto oneskilled in the art as the description proceeds, this invention residesin the novel construction, combination, and arrangement of partssubstantially as hereinafter described and more particularly defined bythe appended claims, it being understood that such changes in theprecise embodiment of the herein disclosed invention are meant to beincluded as come with the scope of the claims.

DESCRIPTION OF THE DRAWINGS The accompaning drawings illustrate acomplete embodiment of the invention according to the best mode so fardevised for the practical application of the principles thereof, and inwhich:

FIG. 1 is a flow diagram, in blockform, of the system of this inventionshowing utilization at a plurality of ar-.

FIG. 5 is a side view of a level control that may be utilized in themaster tank of the system of this invention; and

FIG. 6 is an electrical schematic diagram of the control circuit of thesystem of this invention.

DETAILED DESCRIPTION Referring now to the drawings, in which likenumeral have been used for like characters, the numerals 11 and 12 inFIGS. 1 through 4 refer to the fluid bulk, or coating material supplysource, which is shown in FIGS. 2 and 3 to consist of a plurality (twoas shown) of barrels, or drums, of coating material. The coatingmaterial, when utilized for applying a coating to the surface of glassarticles is normally a heat decomposable metallic compound in liquidform, such as, for example, titanium tetrachloride, tetraisopropyltitanate, or tin tetrachloride, all of which are commercially available.

The coating material receptacles 11 and 12 are connected by lines, orconduits, 14 and 15, respectively, to

a reservoir 17, which reservoir is automatically maintained filled withliquid coating material from the supply source as described in greaterdetail hereinafter. Reservoir 17 is, in turn; connected through line 18to an electric pump 20, which pump pumps coating material through line21 to master, or main, tank 23.

Master tank 23 has a level indicator 24 therein, the electrical leadsfrom which are conducted through conduit 25 to alarm circuitry 27 whichhas connected therewith alarm indicator 28. This apparatus monitors thelevel in the tank and indicates any level deviation beyond apredetermined maximum or minimum level. Master tank 23 has connectedtherewith through a line 30, one or more slave tanks, indicated in FIG.I as a plurality of four slave tanks 32, 33, 34, and 35. As shown inFIG. 2, only slave tank 32 has been detailed, but it is to beappreciated that a plurality of slave tanks, as indicated in FIG. 1, maybe utilized if found necessary or convenient. Master tank 23 and theslave tanks associated therewith may be of the same size and may beconnected by three-fourths inch lines (as may reservoir 17 also beconnected to master tank 23). In a working embodiment, it was found thattanks with a diameter of about one foot and a height of about 28 inches(about 12% gallon capacity) were operationally satisfactory.

Slave tank 32 is connected through line 37 to associated article coatingstation 42, while, as shown in FIG. 1, slave tanks 33, 34, and 35 may beconnected in like manner through leads 38, 39, and 40, respectively, toassociated article coating stations 43, 44, and 45, re-

. spectively. Article coating stations 42 through 45 have not been shownin detail herein, it being understood that each of these stations mayinclude a hood (not shown) into which vapor that includes heatdecomposable metallic coating compound'is introduced to coat glassarticles with a thin coating of metal oxide as they pass through thehood while the articles retain heat of formation above the decompositiontemperature of the heat decomposable metallic compound utilized. Articlecoating stations of this type, as well as stations utilizing a tank ofcoating material through which an inert gas (such as dry air) is passedto supply the needed vapor that includes the coating material'are knownin the prior art and examples of such prior art have been set forthhereinabove and should be consulted for a description in greater detail,if needed.

In a working embodiment of this invention, stainless steel and/or Tefloncomponents were used throughout and along with welded joints provided asatisfactory closed system.

Referring now to FIG. 2 of the drawings, the coating material supply isshown to include barrels, or drums, l1 and 12. These drums may beconventional and the material to be utilized is stored therein,preferably in liquid form. Such material may, for example, be titaniumtetrachloride, tetraisopropyl titanate or tin tetrachloride, as broughtout hereinabove, where the coating material is to be utilized for thecoating of glass containers. The barrels, or drums, l 1 and 12 arepreferably easily removable for supply replenishment and other purposes,and accordingly, are mounted on U-shaped support frame 47 the legs 48 ofwhich have wheels 49 conventionally mounted near the free ends and thecentral portion of which has a wheel 50 conventionally pivotably mountedthereon. Upstanding supports 52 extend from frame 47 rearwardly ofwheels 49 and the free ends of supports 52 are conventionally secured tothe sides of the associated barrel (11 or 12) at 53 so that the barrelsmay pivot in a vertical plane to facilitate connection to reservoir 17and/or emptying or cleaning of the barrel. To provide stability ofoperation, the lower rear portion of the barrel can rest on the top offrame 48 above wheel 50 (and could, of course, be blocked conventionallyat any desired angle).

Barrels 11 and 12 are operationally positioned adjacent to reservoir 17,as shown best in FIG. 2, so that each barrel can be connected with bothan outlet line (14 or 15) and with an air return.

The air return to each of the barrels 11 and 12 is provided by means ofa partial double conduit. As shown in FIG. 2, air return 56 for barrel11 has conduit 57 connected to barrel 11 and parallel connected conduits58 and 59 connected between reservoir 17 and conduit 57, the latterconnection being achieved through a valve 60 which connects conduit 57to either conduit 58 or 59 depending on valve positioning (this valvecould also be utilized to disconnect conduit 57 from both conduits 58and 59 and eliminate the unnumbered separate shut-off valve indicated inconduit 57 near the top of barrel l1).

Conduit 58 is connected with reservoir 17 by means of coupling, orfitting, 62 which extends into the reservoir 17 a short distance,preferably about one inch. Fitting 61, which connects conduit 59 withreservoir 17 opens only into the top of the reservoir and does notextend downwardly therein, as best shown in FIG. 3.

In like manner, the second barrel 12 is likewise connected with thereservoir. As shown in FIGS. 2 and 3, air return conduit 64 includesconduit 65 connected to the top portion of barrel 12 through anunnumbered shut-off valve, whileconduits 66 and 67 connected inparallel, are connected to reservoir 17 and to conduit 65 through valve68. Valve 68, like valve may be utilized to open conduit to either ofconduits 66 and 67 or to neither of them. Fitting 69 does not extend.into reservoir 17 and opens conduit 67 to the top of the reservoir whilefitting 70, like fitting 62, extends into reservoir 17 a short distance,preferably about 1 inch. If desired, fittings 61 and 69 may also extendinto the reservoir a short distance, and if this occurs, fittings 62 and70 must extend further into the reservoir by about 1 inch than dofittings 61 and 69.

In addition to the inlets to and outlets from the top of reservoir 17 tothe supply drums 11 and 12, an air supply line 72 is also connected toreservoir 17 by means of a fitting 73 which opens the air supply lineinto the top of the reservoir. Line 72 is connected with a pressurizedsource (not shown) so that a small pres sure is maintained within thereservoir. This may be readily accomplished by connnecting line 72 to asource of dry air (i.e., air dried to a very high degree, such as to adew point of -50 F. or more) having a pressure of not more than about 1pound per square inch (1 p.s.i.).

As shown in FIGS. 2 through 4, reservoir 17 includes an elongatedcylindrical body portion 75 both ends of which are closed by end plates76 (front) and 77 (rear). Reservoir 17 is sized and positioned withrespect to the bulk source utilized (barrels l1 and 12 as shown) so thatthe reservoir can remain filled with liquid by gravity feed from thestorage source to the reservoir. As shown in FIGS. 2, 3, and 4, thispositioning arrangement is preferably with the top of the reservoirabout level or just below the bottom of barrels 11 and 12. In a workingembodiment of this invention, two conventional 55 gallon drums wereutilized as storage barrels 11 and 12 and a reservoir of about 15 inchesdiameter and a length of about 6 feet was satisfactory to give thedesired performance. The reservoir (and conduits), must of course, besized to handle the expected maximum flow of coating material andpositioned in view of known factors such as atmosphereic pressuredifferentials to be encountered.

The air returns 56 and 64 from reservoir 17 to the drums l1 and 12provide an automatic feed selection arrangement. Since the barrels areconnected to a double conduit return, anoperator, after initiallyconnecting two barrels filled with coating material to the reservoir,turns valve 60 (for example) to connect reservoir 17 with conduit 59 andturns valve 68 to connect reservoir 17 with conduit 66. Since conduit 59is connected with the top of the reservoir while conduit 66 is connectedwith fitting 70 which extends into the barrel, the reservoir is filledfrom drumll since an uncovered air return is provided through conduits57 and 59, while the air return conduit 66 is effectively closed sincefitting 70 extends into the liquid in the filled barrel to preclude areturn of air to drum 12. This arrangement causes the coating materialfrom drum 11 to be gravity fed into the reservoir to keep the reservoirfull until drum 11 is empty. After drum 11 empties and the level ofcoating material in the reservoir drops to a point sufficiently low toexpose the lower end of fitting 70, air is then permitted to return todrum 12 and this drum would then be emptied into the reservoir tomaintain Y the reservoir at a level roughly equal to the bottom offitting 70 extending into the drum (preferably about 1 inch). Anoperator would then avoid depletion of the coating material supply byconnecting a new barrel in place of barrel 11 (or by filling barrel 11).At this time,

' the operator would preferably change valve 68 to connect barrel 12through conduit 67 (which would then allow the reservoir to completelyfill since conduit 67 opens into the top of reservoir 17) and changesvalve so that conduit 58 is connected with the barrel which conduit isconnected to fitting 62 which extends down into the barrel) so that thecontents of barrel 11 would not then feed into the reservoir untilbarrel 12 was empty. While not shown, a level indicator could beconventionally mounted in barrels 11 and 12 to facilitate manualmonitoring of the barrels in conventional manner. If fittings 61 and 69extend into the reservoir so that fittings 62 and 70 extend into thereservoir about 1 inch further than do fittings 61 and 69, the level inthe reservoir will, of course, at no time be higher than the shortest ofthese fittings. Operation will be unaffected, however, and such anarrangement may often be preferred.

Reservoir 17 is connected to conduit 18 through fitting 79 which opensfrom the bottom of the reservoir through front end plate 76. The outletconduit is connected to pump 20, as shown in FIG. 2, and if desired ,ashut-off valve can be inserted into the line, as indicated in FIG. 2.Pump 20 is preferably utilized in a constantly energized state duringnormal operation to thus maintain a constant flow of material betweenthe main tank 23 and the reservoir 17. The inflow to main tank 23 ismaintained through conduit 21 from the pump 20 into the bottom portionof the main tank 23 through fitting 83. A return conduit 80 is connectedto reservoir 17 from main tank 23 with the return being connected toreservoir 17 at the top center thereof through fitting 81, and thereturn conduit is connected to the upper portion of the main tank 23 bymeans of fitting 84, as shown in FIG. 2. Fitting 84 for returnconduit'80 preferably opens into main tank 23 a short distancedownwardly from the top of the tank so that a level control can beinserted into the tank as is brought outmore fully hereinafter. It isfound that with a level control as shown in FIG. 5, the return conduitpreferably opens into main tank 23 about nine inches below the top ofthe tank.

The coating material from the main tank to the slave tanks is fedthrough conduit 30 connected to the main tank by means of fitting 85which opens into the bottom portion of the main tank as shown in FIG. 2.A shut-off valve can also be inserted into this line if desired. Inaddition, the top of main tank 23 has an aperture to receive a fitting86 therein which allows insertion of a level indicator such as levelindicator 24 shown in FIG. 5. The electrical connection of the levelcontrol indicator 24 is by means of a plurality of wires leading fromswitches in the level control unit. These wires (four as shown in FIG.6) are conducted through conduit 25 to the alarm circuitry 27, as isbrought out more fully hereinafter (conduit 25 can, of course, beeliminated and the wires conducted to the alarm circuitry withoutadditional covering if desired).

As is shown in FIG. 2, slave tank 32 (this being the only slave tankdetailed in FIG. 2 although it is to be ap pr'eciated that additionalidentical slave tanks, such as slave tanks 33, 34, and 35, may beutilized as brought out hereinabove) is connected to conduit 30 at thebot tom portion thereof by means of fitting 88 so that when the mastertank 23 is connected with one or more slave tanks by conduit 30 as anopen line, the connected slave tanks are gravity fed from the mastertank and hence will fill to a predetermined level determined by therelative positioning of each slave tank with respect to the master tank.If, as preferred, the slave tanks utilized are positioned at the samelevel as the master tank, then the slave tanks will fill to the samelevel as the master tank by gravity feed. Each slave tank may, ifdesired, have a shut-off valve which can be closed, as can conduit 30,as indicated in FIG. 2.

As also shown in FIG. 2 slave tank 32 has an air inlet at the top of thetank with conduit 90 leading from a pressurized air supply source (notshown) to fitting 91 with the fitting extending into the bottom portionof the tank as indicated in FIG. 2. Dry air is conventionally injectedinto the slave tank (preferably at about 10 p.s.i. or less) and bubbledtherethrough so that vapor laden with coating material may thereafter beconducted from the slave tank through conduit 37 to the article coatingstation for applying a thin coating to glass articles as is described ingreater detail hereinabove.

Referring now to FIG. 5, a level control is shown which can be utilizedwith the system of this invention to provide an indication of leveldeviations in the master tank beyond predetermined minimum and maximumlevels. As shown, a shaft, or tube, 96 extends downwardly into the maintank and may be secured to the top thereof by a shaft connector 97 tothe bottom of the mounting plug, or fitting, 86. A shaft end fitting 98is conventionally secured to the bottom of shaft 96 to seal the same,while a plurality of shaft unions 100, 101, and 102 are spaced along theshaft, as shown in FIG. 5. Obviously shaft 96 could also consist of aplurality of short tubes connected between the tube unions and tube endsin conventional fashion if desired. Shaft 96 is preferably one-half inchdiameter tubing and the entire length of the level indicator belowfitting 86 is about l6 inches.

A conventional level responsive switching station 104 is received onshaft 96 with the station being constrained to movement axially alongthe shaft between unions 100 and 101. Station 104 is preferably nearlyspherical in shape, as shown in FIG. 5, and, when in position on thevertically extending shaft 96, will normally assume a position with thelower end in engagement with union 101 due to the downward pull ofgravity. Station 104 is buoyant, however, as by being air filled or offloatable material, so that the station 104 will be moved upwardly whenthe liquid level rises sufficiently to overcome the force of gravity. Asshown, station 104 can be moved upwardly due to a rise in the liquidlevel within the master tank until the top of the station is inengagement with union 100. As indicated in FIG. 6, station 104 includesa switch which is open when the station is in one position relative tothe shaft and closed when in a second position. As indicated in FIG. 5,the

' switch is normally closed when the station is contiguous to union 101and open when displaced upwardly by the liquid level in the tank so asto be contiguous to union 100.

In like manner, a conventional level responsive switching station 105 isreceived on shaft 96 with the station being constrained to axialmovement along the shaft between shaft end fitting 98 and union 102.Station 105 is identical to station 104 and, when positioned on shaft96, assumes a position, due to gravity, with the bottom portion inengagement with end fitting 98 except when displaced upwardly due to theliquid level in the tank, the limit of upward movement ofvstation 105being with the top portion of the station in engagement with union 102.Like station 104, station 105 also includes a switch which is open whenthe station is in one position relative to the shaft and closed when ina second position. As indicated in FIG. 5, the switch is normally closedwhen the station is displaced upwardly due to liquid within the tank soas to be contiguof field power on light 121 (the other sideof which isous to union 102 and open when the liquid level falls sufficiently toallow the station to drop downwardly along the shaft so as to becontiguous to end fitting 98.

Since station 104 is the uppermost station of the pair of stations whenpositioned in master tank 23, this station senses a liquid level that ispredetermined to be higher than, or at least at a maximum height level,de-

sired within the tank, while the lower station senses a drop in liquidlevel to a level at least equal to a minimum acceptable level, or lower.In normal operation, the liquid level is maintained between stations 104and 105 (the outlet from master tank 23 at fitting 84 is preferablymidway beweeen the stations) so that station 105 is normally immersed inliquid and hence is held in its uppermost position, while station 104 isnormally above the liquid level and hence is normally in its lowermostposition, as is indicated in FIG. 5. Stations 104 and 105 may preferablybe displaced a maximum of about one-half inch upwardly or downwardly onshaft 96 to change the state of the switch associated with each, andduring normal operation each station (which has a diameter of about 2inches) is maintained about 3 /2 inches from the normal fluid level in aworking embodiment of this invention. Other level indicators could, ofcourse, be utilized in this invention, if desired, it being onlyimportant that the fluid level be sensed and at a predetermined point anindication thereof produced, such as a switch being caused to'changestates (between open and closed positions).

Both stations 104 and 105 have leads extending from the switches therein(as indicated in FIG. 6) and these leads are conducted upwardly throughshaft 96 (not shown) and out of the master tank through fitting 86 andconduit 25 to the alarm circuitry 27. As indicated in FIG. 2, alarmcircuitry 27 is located at main panel 107. Main panel 107 is connectedwith' an auxiliary, or field, panel 108, preferably located near thestorage supply which, as brought out hereinabove, may be preferablyremotely located'with respect to the tanks and coating stations. Aconduit 109 is shown connecting the two panels and it is to beunderstood that the necessary leads may be conducted therethrough toaccomplish the electrical wiring arrangement asset forth in FIG. 6. Thepanels, both main and field, show a plurality of switches and lights(not numbered), and it is to be understood that this is merely arepresentation of placement to carry forth the electrical embodimentmore specifically detailed in FIG. 6.

Referring now to FIG. 6, the electrical schematic diagram of the systemis shown. As can be appreciated, the only electrical circuitry requiredin the system is for motor control, the remainder of the electricalsystem being for automatic level monitoring.

Power for the system is conventionally supplied from a 110 volt AC, 60cycle source (not shown) through leads 111 and 112. Fuses 113 and 114are supplied in the line with fuse 113 being connected to lead 116 andfuse 114 is connected to line 117. Line 116 is connected through mainpower switch 118 to. line 119 so that the main power lines for thecircuit consists of lines 117 and 119. Lead 120 connects line 119 to oneside connected to line 117 by lead 122) and to one side of power onlight 123 (the other side of which is connected to line 117 by lead124). As indicated in FIG. 6, these lights are preferably amber incolor, and power on light 123 is on the main panel 107 while field poweron light 121 is on the auxiliary, or field, panel 108.

Lead 125 connected connects one side of test switch 126 to lead 119,while lead 127 connects the other side of the test switch to a pluralityof components including a connection to one side of pump on light 128(the other side of which is connected to line 117 through lead 129).Pump on light 128 is at the main panel and is preferably green, asindicated in FIG. 6. Lead 131 connects line 119 to one side of fieldstop switch 132, the other side of this switch being connected by lead133 to one side of stop switch 134. Both stop switches 132 and 134 arenormally closed with stop switch 134 being located on the main panel107, while field stop switch 132 is located on the auxiliary panel 108.Stop switch 134 is connected by lead 135 to field start switch 136, mainstart switch 137, and one side of switch 138, all of which are normallyopen with switches 136 and 137 being on the auxiliary and main panels,respectively. Switch 138 is connected in series with normally openswitch 139, with switches 136, 137, and 139 being connected to lead 141which is also connected to lead 127. One side of pump motor controller142 is connected to lead 141 (the other side of which controller isconnected to lead 117 through lead 143). In addition, one side of fieldpump on light 144 is likewise connected to lead 141, while the otherside is connected to lead 117 through lead 145. Field pump on light 144is located at the auxiliary panel 108 and is preferably green in color,while pump motor controller 142 is an AC control relay that controlsactuation of switches 138 and 147.

Lead 146 connects one side of normally open switch 147 to line 119,while the other side of switch 147 is connected by lead 148 to motor 150of pump 20, with the other side of the motor being connected to line 117through lead 151. Lead 152 connects lead 119 to one side of normallyclosed switch 153 with the other side being connected through lead 154to fluid level alarm light 155, the other side of whichsisconnectedthrough lead 156 to lead 117. Fluid level alarm light 155 is preferablyred in color and is located near the main panel 107 (this light isindicated in FIG. 2 as light 28). This alarm indicator could, of course,also include a bell or other indicator as desired.

Lead 157 connects lead 119 to the center input of a conventional singlepole double throw (SPDT) switching arrangement 158 indicated in blockform in FIG. 6. This switching arrangement includes leads 159 and 160which are connected to high fluid level switch 161 within high levelfluid sensing station 104 (leads 159 and 160 thus extend from station104 to panel 107 through conduit 25). The state of switch 161, whichstate is determined by the positioning of station 104 on shaft 96, thusdetermines which of the two outputs of switching arrangement 158 will beconnected with lead 157. One output from switching arrangement 158 isconnected by lead 162 to the field high fluid level light 164 (the otherside of which is connected by lead 165 to line 117) and to high fluidlevel light 166 (the other side of which is connected by lead 167 toline 117). These lights are preferably red in color and are located inthe main (light 166) and auxiliary (light 164) panels. The other outputfrom the switching arrangement 158 is taken through lead 168 tothecenter input of a second conventional single pole double throw (SPDT)switching arrangement 186. Like switching arrangement 158, switchingarrangement 186 has leads 169 and 170 connected to the level indicator24, with leads 169 and 170 extending through conduit 25 and shaft 96 tolow fluid level switch 171 within low level fluid sensing station 105.The state of fluid level switch 171 depends on the positioning ofstation 105 on shaft 96, and the state (either open or closed) of switch171 determines which output from the switching arrangement will beconnected with lead 168. One output from switching arrangement 186 isconnected by lead 173 to one side of field low fluid level light 174(the other side of which is connected through lead 175 to line 117) andto one side of low fluid level light 176 (the other side of which isconnected by lead 177 to line 117). These lights are preferably red incolor and are found at the main (light 176) and auxliary (light 174)panels. The other output from the switching arrangement 186 is takenthrough lead 178 to controller 180 the other side of which is connectedto line 117. Controller 180 is an AC contactor which controls the stateof switches 139 and 153.

In operation, power is applied to the system by actuating power switch118 from an off position to an on position. This will energize the poweron lights to show that power is available at the system. If desired,test switch 126 can then be actuated to the on position to energize pumpon lights 128 and 144 and energize pump motor controller 142 to closeswitch 147 and thereby energize pump motor 150. Actuation of the testswitch 126 to the off position will then de-energize the pump on lightsand controller to thus de-energize the motor. If the liquid level isbelow the predetermined minimum level as established by the position ofstation 105 of the level indicator 24 within master tank 23, switch 171will be open and controller 180 will remain de-energized when power isapplied. This will cause switch 153 to be in the normally closedposition and will thus allow fluid level alarm 155 to be energized untilthe level is brought up sufficiently in the master tank to close theswitch and energize controller 180 to open switch 153 and de-energizethe alarm.

To start the pumping operation, it is necessary to close either startswitch 137 or field start switch 136 to energize pump motor controller142 and thus close switch 147 to energize the pump motor 150. Pump motorcontrol 142 will not remain energized, however, if the start or fieldstart button is opened prior to the time that the liquid level risessufficiently in the master tank to cause the low fluid level switch 171to be actuated from a low level indication. Only after switch 171 hasbeen actuated from a low'level indication is it possible for controller180 to be energized to close switch 139 and establishra holding circuitaround the start switches (switch 138 is closed by energization ofcontroller 142). Pump 150 will then remain energized so long as the pumpmotor controller 142 remains energized. In normal operation, the pumpwill constantly pump coating material into the master tank and the levelwill remain constant withthe excess over that utilized at the slavetanks being returned to the reservoir via the return line (the returnline opens into the master tank about mid-way between the high and lowlevel sensing stations 104 and Termination of pump energization canoccur by power disruption to the system, by actuatingthe power switch118 to the off position, or by opening either stop switch 132 or 134. Inaddition, automatic termination of pump energization will occur if theliquid level in the main tank should either rise or fall to a level tochange the state of either switch 161 (high level) or switch 171 (lowlevel). If this should occur, controller 180 will be de-energized andthis will close switch 153 to actuate the alarm 155 and open switch 139to de-energize pump motor controller 142 and hence open switch 147 tostop the pump motor 150. If the high level switch 161 is actuated,controller 180 is de-energized by terminating the power thereto andpower is applied to the high fluid level lights 164 and 166. If the lowlevel switch 171 is actuated, controller 180 is likewise deenergized byterminating the power thereto, but in this event power is applied to thelow fluid level lights 174 and 176. After the problem with respect tofluid level in the master tank has been corrected, then normal operationcan be resumed by actuating the start or field start switches. A highlevel could occur, for example, due to a blocked return line to thereservoir, while a low level could occur, for example, due to a lack ofsupply of coating material.

As can be seen from the foregoing, the system of this invention providesa heretofore unavailable means for handling and distributing fluids thatis particularly useful in handling and distributing coating materialsfor use in coating glass articles.

What is claimed is:

1. A liquid handling system, comprising: a slave tank for supplyingliquid to utilization means; a master tank; conduit means for connectingsaid slave tank to said master tank, said slave and master tanks beingpositioned so that predetermined relative liquid levels existtherebetween when said conduit means is open between the slave andmaster tanks; a storage reservoir including a reservoir tank and aplurality of bulk storage tanks, air return means connecting saidreservoir tank and the plurality of bulk storage tanks, said air returnmeans having selectible first and second parallel conduits with a firstconduit extending into said reservoir tank a greater distance than doesthe second conduit so that a first bulk storage tank with a firstconduit selected is precluded from supplying liquid to said reservoirtank until the liquid level falls below said first conduit extendinginto said reservoir tank, while a second of said bulk storage tanks withsaid second conduit selected will continuously provide liquid to saidreserve tank and preclude liquid supply from the first of said bulkstorage tanks until the second of said bulk storage tanks is empty.

2. The liquid handling system of claim 1 wherein said master tank has alevel monitoring means therein, and wherein said system includes analarm indicator connected with said level monitoring means andindicating master tank liquid level deviations beyond predeterminedminimum and maximum levels.

3. A fluid distributing system, comprising: a reservoir; first andsecond storage tanks; first and second conduits connecting said firstand second storage tanks to said reservoir; and first and second'airreturn means connecting said reservoir to said first and second storagetanks, said air return means including means for preselecting andcausing automatic successive supply- 12 ing of fluid from said storagetanks to said reservoir.

4. The fluid distributing system of claim 3 wherein each of said airreturn means includes first and second air return conduits connected inparallel with one another, said first air return conduit extending intosaid reservoir a greater distance than does the second, and wherein eachof said air return means includes a valve for selecting which of saidfirst and second air return conduits are connected with said associatedstorage tank.

5. A liquid handling system for coating material used in applying acoating to glass articles, said system comprising: a slave tank forsupplying coating material in liquid form to coating materialutilization means; a master tank; conduit means for connecting saidslave tank to said master tank, said tanks being positioned so that apredetermined relative liquid level of coating material existstherebetween when said conduit means is open between the tanks; acoating material storage reservoir; and means for connecting saidstorage reservoir to said master tank so that coating material in liquidform is supplied from said reservoirto said master tank to maintain thelevel of coating materials in said master tank substantially constantduring normal operation of the system.

6. A liquid handling system for coating material used in applying acoating to glass articles, said system comprising: a plurality of glassarticle coating stations for receiving glass articles to be coated witha predetermined coating material; a plurality of slave tanks equal innumber to said article coating stations with each said slave tank beingassociated with a different one of the said article coating stations tosupply coating material thereto; a plurality of first conduits forconnecting each of said slave tanks to an associated coating station; amaster tank; second conduit means for connecting said master tank withsaid slave tanks, said tanks being positioned so that when open to oneanother through said second conduit means said tanks attain apredetermined level of coating material relative to one another; areservoir of coating material; third and fourth conduits connecting saidmaster tank with said reservoir, said conduits opening into said mastertank atpredetermined vertically spaced positions; a pump connected withsaid third conduit to cause coating material to be constantly pumped tosaid master tank and the excess then returned to said reservoir; aplurality of bulk storage tanks; a plurality of fifth conduits forindividually connecting each of said bulk storage tanks to saidreservoir; a plurality of sixth conduits for individually providing anair return to each of said bulk storage tanks from said reservoir, eachof said sixth conduits including means to cause automatic successivesupplying of coating material to said reservoir to maintain the fluidlevel therein at predetermined levels; a level sensing device in saidmaster tank; and indicator means conreached.

1. A liquid handling system, comprising: a slave tank for supplyingliquid to utilization means; a master tank; conduit means for connectingsaid slave tank to said master tank, said slave and master tanks beingpositioned so that predetermined relative liquid levels existtherebetween when said conduit means is open between the slave andmaster tanks; a storage reservoir including a reservoir tank and aplurality of bulk storage tanks, air return means connecting saidreservoir tank and the plurality of bulk storage tanks, said air returnmeans having selectible first and second parallel conduits with a firstconduit extending into said reservoir tank a greater distance than doesthe second conduit so that a first bulk storage tank with a firstconduit selected is precluded from supplying liquid to said reservoirtank until the liquid level falls below said first conduit extendinginto said reservoir tank, while a second of said bulk storage tanks withsaid second conduit selected will continuously provide liquid to saidreserve tank and preclude liquid supply from the first of said bulkstorage tanks until the second of said bulk storage tanks is empty. 2.The liquid handling system of claim 1 wherein said master tank has alevel monitoring means therein, and wherein said system includes analarm indicator connected with said level monitoring means aNdindicating master tank liquid level deviations beyond predeterminedminimum and maximum levels.
 3. A fluid distributing system, comprising:a reservoir; first and second storage tanks; first and second conduitsconnecting said first and second storage tanks to said reservoir; andfirst and second air return means connecting said reservoir to saidfirst and second storage tanks, said air return means including meansfor preselecting and causing automatic successive supplying of fluidfrom said storage tanks to said reservoir.
 4. The fluid distributingsystem of claim 3 wherein each of said air return means includes firstand second air return conduits connected in parallel with one another,said first air return conduit extending into said reservoir a greaterdistance than does the second, and wherein each of said air return meansincludes a valve for selecting which of said first and second air returnconduits are connected with said associated storage tank.
 5. A liquidhandling system for coating material used in applying a coating to glassarticles, said system comprising: a slave tank for supplying coatingmaterial in liquid form to coating material utilization means; a mastertank; conduit means for connecting said slave tank to said master tank,said tanks being positioned so that a predetermined relative liquidlevel of coating material exists therebetween when said conduit means isopen between the tanks; a coating material storage reservoir; and meansfor connecting said storage reservoir to said master tank so thatcoating material in liquid form is supplied from said reservoir to saidmaster tank to maintain the level of coating materials in said mastertank substantially constant during normal operation of the system.
 6. Aliquid handling system for coating material used in applying a coatingto glass articles, said system comprising: a plurality of glass articlecoating stations for receiving glass articles to be coated with apredetermined coating material; a plurality of slave tanks equal innumber to said article coating stations with each said slave tank beingassociated with a different one of the said article coating stations tosupply coating material thereto; a plurality of first conduits forconnecting each of said slave tanks to an associated coating station; amaster tank; second conduit means for connecting said master tank withsaid slave tanks, said tanks being positioned so that when open to oneanother through said second conduit means said tanks attain apredetermined level of coating material relative to one another; areservoir of coating material; third and fourth conduits connecting saidmaster tank with said reservoir, said conduits opening into said mastertank at predetermined vertically spaced positions; a pump connected withsaid third conduit to cause coating material to be constantly pumped tosaid master tank and the excess then returned to said reservoir; aplurality of bulk storage tanks; a plurality of fifth conduits forindividually connecting each of said bulk storage tanks to saidreservoir; a plurality of sixth conduits for individually providing anair return to each of said bulk storage tanks from said reservoir, eachof said sixth conduits including means to cause automatic successivesupplying of coating material to said reservoir to maintain the fluidlevel therein at predetermined levels; a level sensing device in saidmaster tank; and indicator means connected with said level sensingdevice to indicate level deviations beyond a predetermined minimum leveland a predetermined maximum level and to terminate pump operation shouldsaid predetermined levels be reached.